Showing papers on "Cloud computing published in 2001"

A cloud resolving model as a cloud parameterization in the NCAR Community Climate System Model: Preliminary results

Abstract: Preliminary results of a short climate simulation with a 2-D cloud resolving model (CRM) installed into each grid column of an NCAR Community Climate System Model (CCSM) are presented. The CRM replaces the conventional convective and stratiform cloud parameterizations, and allows for explicit computation of the global cloud fraction distribution for radiation computations. The extreme computational cost of the combined CCSM/CRM model has thus far limited us to a two-month long climate simulation (December-January) using 2.8° × 2.8° resolution. The simulated geographical distributions of the total rainfall, precipitable water, cloud cover, and Earth radiation budget, for the month of January, look very reasonable.

A fast method for retrieval of cloud parameters using oxygen a band measurements from the Global Ozone Monitoring Experiment

Abstract: The Global Ozone Monitoring Experiment (GOME) on board the ERS-2 is designed to measure trace gas column densities in the Earth's atmosphere. Such retrievals are hindered by the presence of clouds. The most important cloud parameters that are needed to correct trace gas column density retrievals for the disturbing effects of clouds are the (effective) cloud fraction and cloud top pressure. At present, in the operational GOME data processor an effective cloud fraction is derived for each pixel, but cloud top pressure is assumed a priori and is deduced from a climatological database. Here we report an improved cloud retrieval scheme, which simultaneously retrieves the effective cloud fraction and cloud top pressure from GOME data. This algorithm, called Fast Retrieval Scheme for Clouds from the Oxygen A band (FRESCO), makes use of reflectivities as measured by GOME inside and outside the oxygen A band (758–778 nm). For validation, the results of FRESCO are compared to effective cloud fractions and cloud top pressures derived with standard methods from colocated measurements made by the Along Track Scanning Radiometer-2 (ATSR-2). The brightness temperatures of the cloudy pixels as measured by ATSR-2 are related to cloud top pressures using temperature profiles from the European Center for Medium-range Weather Forecasts model. Generally, the results from FRESCO and ATSR-2 agree reasonably well. For the effective cloud fractions the average difference (based on a comparison of 322 points) is 0.04; the standard deviation is 0.09. For the cloud top pressures, only points with an effective cloud fraction larger than 0.1 have been compared. For these 236 points the average difference in cloud top pressure is 65 hPa, and the standard deviation is 92 hPa.

Simulations of Trade Wind Cumuli under a Strong Inversion

Abstract: The fifth intercomparison of the Global Water and Energy Experiment Cloud System Studies Working Group 1 is used as a vehicle for better understanding the dynamics of trade wind cumuli capped by a strong inversion. The basis of the intercomparison is 10 simulations by 7 groups. These simulations are supplemented by many further sensitivity studies, including some with very refined grid meshes. The simulations help illustrate the turbulent dynamics of trade cumuli in such a regime. In many respects the dynamics are similar to those found in many previous simulations of trade cumuli capped by weaker inversions. The principal differences are the extent to which the cloud layer is quasi-steady in the current simulations, evidence of weak countergradient momentum transport within the cloud layer, and the development and influence of an incipient stratiform cloud layer at the top of the cloud layer. Although many elements of the turbulent structure (including the wind profiles, the evolution of cloud-base height, the statistics of the subcloud layer, and the nature of mixing in the lower and middle parts of the cloud layer) are robustly predicted, the representation of the stratiform cloud amount by the different simulations is remarkably sensitive to a number of factors. Chief among these are differences between numerical algorithms. These sensitivities persist even among simulations on relatively refined grid meshes. Part of this sensitivity is attributed to a physically realistic positive radiative feedback, whereby a propensity toward higher cloud fractions in any given simulation is amplified by longwave radiative cooling. The simulations also provide new insight into the dynamics of the transition layer at cloud base. In accord with observations, the simulations predict that this layer is most identifiable in terms of moisture variances and gradients. The simulations help illustrate the highly variable (in both height and thickness) nature of the transition layer, and we speculate that this variability helps regulate convection. Lastly the simulations are used to help evaluate simple models of trade wind boundary layers. In accord with previous studies, mass-flux models well represent the dynamics of the cloud layer, while mixing-length models well represent the subcloud layer. The development of the stratiform cloud layer is not, however, captured by the mass-flux models. The simulations indicate that future theoretical research needs to focus on interface rules, whereby the cloud layer is coupled to the subcloud layer below and the free atmosphere above. Future observational studies of this regime would be of most benefit if they could provide robust cloud statistics as a function of mean environmental conditions.

Real-Time Cloud Rendering

Abstract: This paper presents a method for realistic real-time rendering of clouds suitable for flight simulation and games. It provides a cloud shading algorithm that approximates multiple forward scattering in a preprocess, and first order anisotropic scattering at runtime. Impostors are used to accelerate cloud rendering by exploiting frame-to-frame coherence in an interactive flight simulation. Impostors are shown to be particularly well suited to clouds, even in circumstances under which they cannot be applied to the rendering of polygonal geometry. The method allows hundreds of clouds and hundreds of thousands of particles to be rendered at high frame rates, and improves interaction with clouds by reducing artifacts introduced by direct particle rendering techniques.

Reshaping the Theory of Cloud Formation

Abstract: Man-made aerosols are believed to have a strong influence on cloud optical properties and albedo, with a radiative forcing opposite in sign to that exerted by greenhouse gases. The uncertainties associated with this indirect aerosol forcing are, however, very large. In their Perspective, Charlson et al. discuss recent insights into cloud formation. The results indicate that current estimates of both the magnitude and the uncertainty of indirect aerosol forcing may be too low.

Cloud effective particle size and water content profile retrievals using combined lidar and radar observations: 1. Theory and examples

Abstract: In this paper, a novel lidar/radar method for simultaneously determining cloud particle effective size profiles (for water and ice clouds) and the lidar attenuation profile is described. Simulations and application to real data show that this procedure can be quite robust even in cases where significant lidar attenuation is present. In addition, the concept of a suitable lidar/radar effective particle size is introduced, and the determination of water contents for both water and ice clouds using this effective size together with the radar reflectivity profile is discussed. This paper concludes by presenting examples of effective size profiles and water content profiles inferred from measurements made during the Dutch Clouds and Radiation (CLARA) campaign. In a companion paper, it is demonstrated that the results of the inversion procedure compare favorably with infrared radiometer measurements as well as with in-situ measurement results.

Precipitation estimations from geostationary orbit and prospects for METEOSAT Second Generation

Abstract: For over two decades operational rainfall estimations from geostationary satellites have represented an ambitious aspiration of scientists and an identified need of operational meteorologists. A wide variety of infrared and combined visible and infrared methods have been proposed for the identification of suitable relationships between satellite-observed cloud top radiative features and rainfall at the ground. Microwave-based retrievals, however, correlate rainfall and internal cloud microphysical features more successfully. The most significant limitation, however, is the indirect character of the retrieval that correlates microphysical and dynamical cloud characteristics with rain amounts at ground level. METEOSAT Second Generation signals a new era for geostationary satellites with its new 12 channel imager SEVIRI and 15 minute full-disk image repeat cycle. SEVIRI is expected to contribute significantly to a better characterisation of clouds and atmospheric stability by means of improved infrared calibration, radiometric performances, imaging frequency and multispectral image analysis. The significant increase of multispectral cloud observations is expected to provide new data for the improvement of rainfall estimations from geostationary orbit. The anticipated progress from enhanced imaging frequency and multispectral data for the definition of new techniques is discussed. Considerations for operational applications, chiefly for nowcasting, are also provided as they are the main goal of the satellite. Future developments and synergies with other geostationary and polar orbiting instruments, passive and active, are finally considered as the ultimate strategy for more accurate instantaneous rainfall estimations at all latitudes. Copyright © 2001 Royal Meteorological Society

Cloud cover variations over the United States: An influence of cosmic rays or solar variability?

Abstract: To investigate whether galactic cosmic rays (GCR) may influence cloud cover variations, we analyze cloud cover anomalies from 1900–1987 over the United States. Results of spectral analyses reveal a statistically significant cloud cover signal at the period of 11 years; the coherence between cloud cover and solar variability proxy is 0.7 and statistically significant with 95% confidence. In addition, cloud data derived from the NCAR Climate System Model (CSM) forced with solar irradiance variations show a strong signal at 11 years that is not apparent in cloud data from runs with constant solar input. The cloud cover variations are in phase with the solar cycle and not the GCR. Our results suggest that cloud variabilities may be affected by a modulation of the atmospheric circulation resulting from variations of the solar-UV-ozone-induced heating of the atmosphere.

The Cloud, Aerosol and Precipitation Spectrometer (CAPS)—A New Instrument for Cloud Investigations

Abstract: A new airborne particle spectrometer has been developed with the same measurement capabilities of the Forward Scattering Spectrometer Probes (FSSP) models 100 and 300 (FSSP-300 and FSSP-100), two-dimensional optical imaging probe (2D-OAP), the Multiangle Aerosol Spectrometer Probe (MASP) and hot-wire liquid water probe, but with a single integrated system. The cloud, aerosol and precipitation spectrometer (CAPS) measures particles from 0.35 μm to 1.55 mm in diameter and liquid water content (LWC) from 0.01 to 3 g m -3 . In addition to combining five probes into one, it measures airspeed at the sample volume and transmits a data stream that requires no special interfaces to communicate with most computers.

Stability and density management in Douglas-fir plantations

Abstract: , before they are employed” (p. 917).As a forest modeler with 25 years of experience, I cer-tainly agree with this warning to users of growth models,and as the primary architect and developer of ORGANON, Iam always concerned when users, such as the authors, raiseconcerns about the predictive ability of the model. Unfortu-nately, the authors’ description of the data sets used in theiranalysis was so vague (i.e., “…a representative plantation ata variety of initial Douglas-fir densities;” p. 913) that it wasimpossible to reproduce and examine their results directly.This problem was resolved by contacting the senior authorwho promptly supplied the missing detailed description ofthe data and copies of the initial tree lists used to make theORGANON runs.A close examination of these data and of the methods andresults that were reported by the authors indicates that thereare at least three problems with their application of the twoORGANON versions that seriously cloud the veracity oftheir findings.(1) The starting tree lists used as input to ORGANON forthe six planting densities were generated by the authors(J.S. Wilson, by e-mail), resulting in unrealistic treelists. The lack of realism is demonstrated in the authors’Fig. 4, which shows that the initial values of H/D

Cloud and Aerosol Research Capabilities at FARS: The Facility for Atmospheric Remote Sensing.

Abstract: Since October 1987, the University of Utah Facility for Atmospheric Remote Sensing (FARS) has been applied to the probing of the atmosphere, concentrating on the study of high–level clouds. Regular FARS measurements, which currently total ~3000 h of ruby lidar polarization data, have been directed toward basic cloud research, remote sensing techniques development, and to improving satellite cloud property retrieval methods and GCM predictions by providing climatologically representative cloud datasets and parameterizations. Although the initial studies involved mainly the ruby lidar, the facility has steadily evolved to include a range of visible, infrared, and microwave passive remote sensors, and state–of–the–art, high–resolution dual–wavelength scanning lidar and W–band Doppler radar systems. All three active systems display polarization diversity. In this paper are reviewed the specifications of FARS instrumentation and the research programs to which they have been applied. Four multiple remo...

Cloud effective particle size and water content profile retrievals using combined lidar and radar observations: 2. Comparison with IR radiometer and in situ measurements of ice clouds

Abstract: A new combined iidar/radar inversion procedure has been developed for cloud effective radius and water content retrievals. The algorithm treats the lidar extinction, derived effective particle size, and multiple-scattering effects together in a consistent fashion. This procedure has been applied to data taken during the Netherlands Cloud and Radiation (CLARA) campaign and the Cloud Lidar and Radar Experiment (CLARE'98) multisensor cloud measurement campaign. The results of the algorithm compare well with simultaneous IR radiometer cloud measurements as well as with measurements made by using aircraft-mounted two-dimensional probe particle-sizing instruments.

An overview of pervasive computing

Abstract: he importance of pervasive computing is rapidlyincreasingwith the current trend toward universal presence of mobile computing, computer networks, and wireless communications ineveryday life. In thelastdecade, there has been a dramatic increase in the use of companion devices and embedded computing devices. For example, wirelessly connectcd organizers and smart phones are becoming popular, and digital computing in some form is now an integral part of numerous evcryday appliances. This has led to a change in thc waywe perceive computing andcomputers. Computers are no longer standalone special-purpose machines to beusedbyexperts; rather, they arc ubiquitously present in a networked environment to scrve myriad needs of everyday life. The change in our perception of computing and computing devices, and their ever increasing presence in our everyday life is the subject of the new ficld known as pervasive computing. The word pervasive

Numerical study on cloud lines over an urban street in Tokyo

Abstract: `Kanpachi Street Cloud (KSC)' is an unusual small-scalecumulus cloud line visible during calm summer conditions over a major street in the Tokyo metropolitanarea. In order to understand the mechanism leading to the formation of this cloud line,numerical simulations have been performed using the Regional Atmospheric Modelling System.The general characteristics of the simulated KSC agree well with observations. On alarge-scale view, the KSC can be characterized as a cumulus cloud line generated at the convergenceline of two sea breezes on the western side of Tokyo Bay, while on the microscale view, it resemblesBenard-type thermal convection modified longitudinally by wind shear.

The representation of cloud cover in atmospheric general circulation models

Abstract: This dissertation describes various aspects of improvements made in the representation of clouds in the global forecast model of the European Centre of Medium-Range Weather Fore- casts (ECMWF). Cloud parametrization has long been identified as one of the most crucial and uncertain aspects in General Circulation Models (GCMs) of the atmosphere, which are used for both Numerical Weather Prediction and the simulation of climate. It is therefore important to constantly monitor and improve the performance of cloud parametrizations in those models. The first part of the work describes the implementation of an existing cloud parametrization into ECMWF's forecasting system with special attention to a new treatment of the prognos- tic cloud variables in data assimilation. This is followed by an analysis of the performance of the parametrization during a 15-year long data assimilation experiment carried out in the context of the ECMWF reanalysis project. It is shown that despite an overall good perfor- mance, several weaknesses in the simulation of clouds exist. Subtropical stratocumulus and extratropical cloudiness are underestimated, while the cloud fraction in the trade cumulus areas and in the Intertropical Convergence Zone is overestimated. In the second part of the study detailed revisions of the parametrization of cloud generation by convective and non-convective processes are described. A consistent new description of cloud generation by convection is derived using the mass- ux approach. Furthermore an improved description of the generation of clouds by non-convective processes is introduced. The superiority of the new formulation compared to the existing one is demonstrated and links to other approaches to cloud parametrization are established. The third part of the work studies the role of vertically varying cloud fraction for the descrip- tion of microphysical processes. It is shown that the commonly used approach of representing precipitation in GCMs by means of grid-averaged quantities leads to serious errors in the parametrization of various physical processes such as the evaporation of precipitation, with severe consequences for the model's hydrological cycle. A new parametrization of the eects of vertically-varying cloud fraction based on a separation of cloudy and clear-sky precipita- tion uxes is developed and its performance assessed. It is shown that this parametrization alleviates most of the identied problems and thereby more realistically describes the pre- cipitation physics in the presence of cloud fraction variations. The final part of the dissertation takes a critical look at the way the results of cloud parametrizations are evaluated today. A number of studies using a variety of data sources and modelling approaches are described and the need for a coordinated use of the various existing validation techniques is highlighted. A strategy to achieve such coordination is proposed. This work provides contributions to virtually all facets of the development of cloud parame- trizations. It combines theoretical aspects with the use of a variety of modelling approaches and data sources for the assessment of the performance of the parametrization. All model improvements described here are now part of the operational version of the ECMWF forecast model.

Wavelet Analysis of Simulated Tropical Convective Cloud Systems. Part I: Basic Analysis

Abstract: A wavelet analysis of a three-dimensional 7-day explicit simulation of the tropical cloud systems in the Global Atmosphere Research Programme (GARP) Atlantic Tropical Experiment Phase III is performed. Three physically distinct regimes (squall line, nonsquall cloud cluster, and scattered convection) in a doubly periodic domain are analyzed using discrete Meyer wavelets. These wavelets are complete and facilitate the inversion of the decomposed modes. The full wavelet spectra well characterize the spatial localization of each physical variable, in particular, the vertical velocity and the condensate fields. The probability distribution of the wavelet coefficients is non-Gaussian despite the horizontal winds, the temperature, and humidity being closely Gaussian in physical space. This demonstrates the effectiveness of the wavelet basis for analyzing cloud system organization. The full wavelet spectrum also selects a preferred spatial orientation of the convective organization in physical space. A p...

Enhancing the scalability and usability of computational grids via logical user accounts and virtual file systems

Abstract: This paper elaborates on mechanisms by which users, data, and applications can be decoupled from individualcomputers and administrative domains. The mechanisms, which consist of logical user accounts and a virtual file system, introduce a layer of abstraction between the physical computing infrastructure and the virtual computational grid perceived by users. This abstraction converts compute servers into interchangeable parts, allowing a computational grid to assemble computing systems at run time without being limited by the traditional constraints associated with user accounts, file systems, and administrative domains. The described approach has already been deployed in the context of PUNCH (the Purdue University Network Computing Hubs), and is unique in its ability to integrate unmodified applications (even commercial ones) and existing computing infrastructure into a heterogeneous, wide-area network computing environment.

Cloud filter for CO retrieval from IMG infrared spectra using ECMWF temperatures and POLDER cloud data

Abstract: Infrared atmospheric measurements provided by space nadir looking remote sensors are affected by the presence of clouds. To obtain cloud-free CO global distributions from the radiance spectra measured by the IMG instrument, we have developed a simple method of spectra selection using skin temperatures provided by the ECMWF model. Information on the cloud cover was provided by the cloud data of the POLDER instrument which flew aboard the same platform as IMG. We show that a filter based on skin temperature, with thresholds of 8 K over sea and 15.3 K over land, allows to remove most of the cloudy cases.

An operational, real-time cloud detection scheme for use in the Antarctic based on AVHRR data

Abstract: A description is given of an automatic cloud detection scheme that has been developed for year-round, routine use on full (1.1 km) horizontal-resolution, five-channel Advanced Very High Resolution Radiometer (AVHRR) satellite imagery of the Antarctic continent and the adjacent ocean areas. The scheme is based on multiple independent tests to determine whether a pixel is cloudy or cloud-free. Tests used include the use of various channel thresholds, inter-channel differences and assessment of the spatial coherence of infrared data. During that part of the year when there is solar radiation, the channel 3 (3.7 m) data are the most valuable as clouds composed of supercooled water droplets can be detected via their high reflectivity against the dark ice surface. The scheme is successful at detecting most types of cloud, but some problems still remain. During the daytime, low-level, optically thin cloud can be difficult to detect, while during the winter, thick, featureless cloud with a temperature that is similar to the surface is difficult to identify. Assessment of the early climatological fields suggests that the scheme gives a realistic distribution of cloud over the southern part of the Antarctic Peninsula and resolves the greater amount of cloud that is present in King George VI Sound and over the Southern Weddell Sea coastal polynya, and the lower cloud fraction down the spine of the Peninsula.

Improved cloud detection in AVHRR daytime and night-time scenes over the ocean

Abstract: Accurate cloud detection is a requirement of many geophysical applications that use visible and infrared satellite data (e.g. cloud climatologies, multichannel sea surface temperature (MCSST)). Unfortunately, a significant source of residual error in such satellite-based products is undetected cloud. Here, a new, computationally efficient cloud detection procedure for both daytime and night-time Advanced Very High Resolution Radiometer (AVHRR) data is developed. It differs substantially from our prior related work. First, a new clustering procedure is used, which produces more homogeneous and distinct clusters than those produced by either our previous work or the ISODATA algorithm of Ball and Hall. Second, the input information vector is reduced in size, incorporates both radiance and spatial components and each component is normalized. These changes improve the clustering/subsequent classification, tend to decrease execution time, and simplify post-processing of the classified (cloud, clear ocean) data ...

Satellite fish forecasting in south china sea

Abstract: Fish forecasting technology has been applied successfully in many countries. However, most of the forecasting methods used in temperate water were unsuitable to be applied in this region. A fish forecasting model suitable to tropical environment has to be developed. This major project involving several objectives and phases to meet the goal of developing a satellite-based fishery forecasting system in the South China Sea is aimed at supporting the national aspirations of developing an efficient offshore fishery. More importantly, it is aimed at providing the basis for alternate ways towards meeting sustainable harvest of fishery resources. The project is now complete, with most of the major objectives met. Project deliverables include an efficient extraction algorithm of sea surface temperature from AVHRR satellite data which includes an automatic geocoding and cloud masking. Model for extracting ocean colour from SeaWifs was also developed. Based from the multi criteria analysis of these oceanographic conditions, a model suitable for the determination of potential fishing zone in tropical water has been developed. This model is then incorporated into a decision support tool referred as the Tropical Fish Forecasting System (TroFFS). TroFFS is a straight forward and easy to learn software tool that will allow user to process and forecast the potential fishing zone. TroFFS builds upon remote sensing and GIS technology by incorporating aspects of PCI's EASI/PACE and ArcView. In an additional capacity, TroFFS can also be used to detect the warm temperature front and the boundaries of upwelling areas. It is best for the prediction of fishing grounds formed by t he oceanographic phenomenon. TroFFS is a cost-effective geomatics system designed specifically for fish forecasting in tropical waters. TroFFS combines remote sensing and spatial analysis functionality with user-guided fish forecasting processes within a f ully customizable and expandable environment. The system can be integrated with the ground satellite receiving that enabling real time fish forecasting and further developed into the National Fish Forecasting System.

The use of three-dimensional analyses of cloud attributes for diabatic initialization of mesoscale models

Abstract: Diabatic initialization of cloud-resolving forecast models such as MM5, RAMS, ARPS, and WRF allows these models to prognose the future of precipitating cloud systems such as snowstorms and thunderstorms that are present at the initial time. This is a solution to one of the most long-standing problems in NWP: the 1to 3-h spin-up of cloud systems caused by the use of traditional dry initialization.

A further study of the method for estimation of SAGE II opaque cloud occurrence

Abstract: Information on vertical cloud distribution is important to atmospheric radiative calculation, general circulation modeling, and climate study. The method used for estimating the vertical structure of opaque cloud occurrence from the solar occultation observations obtained by the Stratospheric Aerosol and Gas Experiment (SAGE) II has been reviewed for further understanding of the nature of the derived cloud statistics. Most importantly, based on the SAGE II tropical observations (1985-1998), the present study illustrates that the derived opaque cloud occurrence at a given altitude is generally independent of the cloud occurrence at other altitudes, except for some anticorrelation between high-level (12.5 km) and low-level (1-3 km) clouds. This feature of the layer cloud frequency independence is also evident when regional data over the Pacific warm pool and the eastern Pacific are examined. The independent information of the layer cloud frequency is significant and makes it possible to use the derived vertical distribution of cloud occurrence to estimate the probability of multilayer clouds. The limitation is that it is difficult to determine how frequently the multilayer clouds are actually overlapping or how frequently thick cloud ( > 1 km) really occurs based on the SAGE II observations alone. A discussion of the SAGE II tropical opaque cloud occurrence in relation to the cloud climatology based on visual observations from surface stations and ships, the International Satellite Cloud Climatology Project data, and the cloud statistics using rawinsonde records is also provided.

Values in the filter bubble Ethics of Personalization Algorithms in Cloud Computing

Abstract: Cloud services such as Facebook and Google search started to use personalization algorithms in order to deal with growing amount of data online. This is often done in order to reduce the “information overload”. User’s interaction with the system is recorded in a single identity, and the information is personalized for the user using this identity. However, as we argue, such filters often ignore the context of information and they are never value neutral. These algorithms operate without the control and knowledge of the user, leading to a “filter bubble”. In this paper, by building on existing philosophical work, we discuss three human values implicated in personalized filtering: autonomy, identity, and transparency.

The use of NWP model surface temperatures in cloud detection from satellite

Abstract: An increasing number of satellite cloud detection methods include the use of Numerical Weather Prediction model (NWP) surface temperatures as a threshold for the thermal infrared cloud detection test. The NWP model surface temperature and the satellite apparent brightness temperature are assumed to correlate well for clear sky. Investigations over Europe in April 1997 indicate that the correlation over land is highly dependent on location and time of day. In this paper, it is shown that this variation of the correlation has a distinct impact on the quality of the infrared cloud detection test. As a result, cloud cover fractions which are retrieved using this thermal infrared test are biased by this effect. This can have serious impact on the quality of cloud climatologies, especially with respect to the diurnal variation of cloud cover fraction. A new method is introduced to equalize the quality of the infrared cloud detection test throughout the day. Threshold values are allowed to be smaller than commonly used and therefore the quality of the infrared test is improved. The method may be applied in both climate research and near real-time processing.

Operational Cloud Detection in GEOS Imagery

Abstract: The bispectral spatial coherence approach for the detection and masking of clouds is revisited with modifications for operational applications to Geostationary Operational Environmental Satellite (GOES) Imager and Sounder data. The approach applies an edge detection algorithm to a "difference" image to identify the edges or contours of the clouds. The difference image is generated as the difference between the 3.9 and 11 micrometer channels of the GOES sensors. This difference image better highlights cloud edges than either image alone and draws upon the emissivity differences in the various channels. The cloud contours are "filled-in" by referencing the thermal gradients in the 11-micrometer channel or difference image associated with the cloud edge. This paper and associate poster will present a preliminary validation of the bispectral spatial coherence approach and will compare the cloud masks generated with this approach to the National Oceanic and Atmospheric Administration/National Environmental Satellite, Data, and Information Service (NOAA/NESDIS) operational cloud products.